Antibodies not directed against the acetylcholine receptor in myasthenia gravis. An immunoblot study.

Sera of 45 patients with myasthenia gravis (MG) and of 30 healthy controls were screened for antibodies against muscle antigens in an immunoblotting solid-phase assay using a preparation of human amputated muscle as the substrate. In each group, the sera showed several bands on the blots. The findings are thought to indicate that antibodies against muscle components are normally present in human sera. Sera from patients or controls could be distinguished by differences in the band staining patterns. It is suggested that antibodies which are not directed against the acetylcholine receptor may nonetheless play an important role in the pathogenesis and clinical course of myasthenia gravis.